This invention relates to a device for inserting an intraocular lens (IOL) into the human eye. With recent advances in IOL technology, cataract surgery has transitioned from being solely a treatment for visual rehabilitation to also being a refractive procedure with the aim of improving visual function and ultimately the patient's quality of life. IOLs that increase visual function are for example aspheric IOLs to compensate for the spherical aberration of the cornea, or toric IOLs to correct corneal astigmatism, or IOLs to correct distance vision. The performance of new IOL designs is highly dependent on the position of the IOL in the optical system of the eye. Depending on the type of correction, even little decentration and tilt of an IOL in the eye may decrease visual quality.
Foldable IOLs made from silicone, soft acrylics and hydrogels have become increasingly popular because of the ability to fold or roll such soft lenses and insert them through a small incision. Such an IOL usually consists of a small plastic lens with plastic side struts, called haptics, to hold the lens in place within the capsular bag inside the eye. Such an IOL may be for example a one piece IOL, the haptic material is the same as the optical material, or a three piece IOL, with haptics made of harder material such as polymethylmethacrylate (PMMA) filaments.
The most common technique for inserting a foldable IOL is through an injector. Such injectors use a plunger to squeeze an IOL through a cartridge into the eye. The single piece acrylic and silicone plate haptic IOLs are the simplest to use with injectors. These designs have haptics that are sturdy and to a certain extent are resistant to damage from the plunger, as it forcefully pushes the IOL through the cartridge. The three piece IOLs are more difficult to inject as the haptics are difficult to fold and more fragile and susceptible to plunger damage. It is known to use a dedicated holding and folding forceps, to insert the folded IOL into the injector cartridge before squeezing the IOL into the eye. One disadvantage of such common technique therefore is that haptics will most likely be deformed during the implantation procedure, due to mechanical stress on the haptics during folding with the forceps and/or during insertion with the injector. As a consequence the position of the IOL in the optical system of the eye may not be correct. An additional disadvantage is that the folding of the IOL requires a separate step when preparing the injector for injecting the IOL. An additional disadvantage is that the insertion of a multipiece IOL is less predictable than a single-piece IOL in terms of tilt and decentration. In addition common injectors are not reliable and easy to handle. Two completely different injector systems are known for insertion of a soft, foldable lens. One injector system consists of an injector body (a handpiece) and a separate cartridge, whereby the injector body is reusable or disposable and the separate cartridge is disposable. Another injector system consists of a preloaded injector, which means the lens is packed within the preloaded injector. One disadvantage of such completely different injector systems is that the handling is completely different. This is a potential risk for a surgeon, because the preparation of the injector and the handling of the injector during insertion into the eye are different, so that additional training is required. In practice usually only one type of injector system is used to avoid the risk of improper operation. It is therefore difficult to change from one type of injector system to the other, which restricts flexibility, and increases the cost for stocking and handling the injector system.
Document EP2343029A1 discloses an IOL injector capable of inserting one-piece and three-piece IOLs into the eye. Using a forceps the IOL has to be taken out from its packaging and has to be placed very carefully into the injector. In particular the haptics have to be placed very carefully in the correct position. Disadvantages of this injector are that inserting the IOL into the injector is difficult and demanding, that the IOL, in particular the haptics might be damaged during insertion of the IOL into the injector, and that the haptics might be damaged when the plunger folds the haptic and squeezes the IOL through the injection tube.
Document WO2012/015300A1 discloses an IOL injector capable of inserting IOLs into the eye. A high pressure is acting onto the haptics when the plunger folds the haptic and squeezes the IOL through the injection tube, therefore the haptics might be damaged.
Document EP2386272A1 discloses a preloaded IOL injector capable of inserting IOLs into the eye. Disadvantages of this IOL injector are that it is difficult to handle when inserting the IOL into the eye, and that handling errors may occur during insertion. In addition the IOL injector is only suitable for preloaded systems.